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40 Engineering Trivia Questions for Kids

The easiest engineering questions in the game, picked for younger players. Every one comes with the answer and a short explanation of why it is right.

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Easy Engineering Questions and Answers

  1. An arch primarily carries loads through what kind of force?

    Compression

    The curved shape of an arch channels loads mainly as compressive forces through its voussoirs or blocks.

    Easy · Also offered: Tension, Shear, Torsion · Source: U.S. National Park Service, Historic masonry arches

  2. Which ancient water-raising device needs no valves, lifts water one pocket at a time, and still drains fields and moves sewage today?

    Archimedes' screw

    Archimedes reportedly encountered the device in Egypt in the third century BC, though screw pumps may already have been irrigating fields there for centuries. The same design still works in reverse, spinning a turbine to generate hydroelectric power from a stream's fall.

    Easy · Also offered: Chain pump, Persian wheel, Shadoof · Source: Encyclopaedia Britannica

  3. What type of energy does a battery store?

    Chemical energy

    A battery stores chemical energy. Reactions between its electrodes and the electrolyte release electrons, and only at that moment does the stored energy become electrical.

    Easy · Also offered: Electrical energy, Thermal energy, Mechanical energy · Source: U.S. Department of Energy

  4. What machine element supports a rotating shaft?

    A bearing

    A bearing supports a rotating shaft while reducing friction between moving parts. Many bearings use balls or rollers to help the shaft turn smoothly.

    Easy · Also offered: A coupling, A gear, A pulley · Source: Encyclopaedia Britannica

  5. Bridge deck joints are sized mainly to absorb movement caused by what?

    Thermal expansion

    Steel and concrete both expand in heat and contract in cold, so a long deck can shift by a noticeable amount between winter and summer. Without a joint to absorb that motion, the movement would crack the deck or crush the supports at each end.

    Easy · Also offered: Traffic vibration, Wind loading, Ground settlement · Source: Federal Highway Administration

  6. What circuit component stores electric charge in an electric field?

    Capacitor

    A capacitor stores separated electric charge and energy in an electric field.

    Easy · Also offered: Resistor, Diode, Relay · Source: U.S. Department of Energy, Capacitors

  7. In chemistry, what is a substance that speeds up a reaction without being used up by it?

    Catalyst

    A catalyst offers the reaction an easier route by lowering the activation energy it has to climb, and comes out of the process unchanged. That is why a tiny amount can keep working on batch after batch.

    Easy · Also offered: Solvent, Electrolyte, Surfactant · Source: U.S. Department of Energy, Catalysis

  8. What chamber turns shaped clay into ceramic?

    Kiln

    A kiln fires shaped clay at high temperatures, transforming it into hard, durable ceramic. The heat removes moisture and triggers chemical changes that permanently strengthen the clay.

    Easy · Also offered: Oven, Furnace, Retort · Source: Smithsonian National Museum of Asian Art, Kiln glossary

  9. What electrical safety device trips during an overload and can be reset afterward?

    Circuit breaker

    A circuit breaker senses too much current, snaps the circuit open, and can simply be switched back on once the fault is cleared. A fuse does the same job by destroying itself, so it has to be replaced every time.

    Easy · Also offered: Thermal fuse, GFCI outlet, Surge suppressor · Source: U.S. Consumer Product Safety Commission

  10. What does CNC mean in machine tools?

    Computer numerical control

    CNC machine tools use computer instructions to control tool movements and operations.

    Easy · Also offered: Continuous nozzle cooling, Central network calibration, Controlled nickel casting · Source: NIST, Smart manufacturing and CNC

  11. What material combines reinforcing fibers with a surrounding matrix?

    Composite

    A composite combines strong reinforcing fibers with a surrounding matrix that binds them together and helps transfer loads. This combination can produce materials that are both lightweight and highly durable.

    Easy · Also offered: Alloy, Ceramic, Polymer · Source: NASA, Composite materials

  12. What does CAD stand for, in engineering and design software?

    Computer-aided design

    Computer-aided design replaced the drawing board, letting a change to one dimension propagate through a whole model.

    Easy · Also offered: Computer-automated drafting, Computerised architectural drawing, Computer-assisted diagramming · Source: Institution of Engineering and Technology

  13. What is a material that lets electric current flow through it easily called?

    A conductor

    Conductors such as copper, aluminium and silver hold their outer electrons loosely, so those electrons drift through the material and carry current with them. Insulators such as rubber and glass hold their electrons tightly, which is why cable is copper wrapped in plastic.

    Easy · Also offered: An insulator, A semiconductor, A resistor · Source: U.S. Energy Information Administration

  14. What structure releases excess water from a dam?

    Spillway

    A spillway provides a controlled route for releasing flows from a dam to the downstream area, especially when water levels are high.

    Easy · Also offered: Aqueduct, Viaduct, Levee · Source: U.S. Department of Energy, Glossary of Hydropower Terms

  15. What vehicle mechanism lets drive wheels turn at different speeds in a turn?

    Differential

    A differential allows driven wheels on the same axle to rotate at different speeds while receiving torque.

    Easy · Also offered: Clutch, Alternator, Radiator · Source: Encyclopaedia Britannica, Differential

  16. What semiconductor component conducts current mainly in one direction?

    Diode

    A diode is a semiconductor component that allows current to flow mainly in one direction while resisting it in the other. Light-emitting diodes (LEDs) are a common type that produce light when current flows through them.

    Easy · Also offered: Transistor, Thermistor, Varistor · Source: Encyclopaedia Britannica, Diode

  17. Industrial distillation separates liquids mainly by differences in which physical property?

    Boiling points

    Distillation separates liquid components by exploiting differences in their boiling points.

    Easy · Also offered: Liquid densities, Solubility limits, Liquid viscosities · Source: U.S. Department of Energy, Distillation

  18. What rotating part stores energy to smooth a machine's motion?

    Flywheel

    A flywheel stores rotational energy and releases it to smooth fluctuations in a machine's motion.

    Easy · Also offered: Crankshaft, Rotor, Pulley · Source: Encyclopaedia Britannica, Flywheel

  19. What process shapes heated metal with repeated blows or pressure?

    Forging

    Forging shapes heated metal through repeated hammering or pressing.

    Easy · Also offered: Casting, Rolling, Extrusion · Source: Forging Industry Association, What is Forging?

  20. An Icelandic power station drills wells to raise steam. What is that steam heated by?

    Earth's internal heat

    Geothermal systems use heat from inside Earth to produce steam or hot fluids for useful energy.

    Easy · Also offered: Sunlight, Wind, Biomass · Source: U.S. Department of Energy, Geothermal basics

  21. Which historic fortification was built in stages over more than two millennia?

    Great Wall of China

    The Great Wall of China was built and rebuilt in stages over more than two thousand years, beginning with defensive walls constructed as early as the 7th century BCE. Its surviving sections stretch for thousands of kilometers across northern China.

    Easy · Also offered: Hadrian's Wall, Antonine Wall, Walls of Constantinople · Source: UNESCO, The Great Wall

  22. In a conventional hydroelectric plant, what does the turbine spin?

    Generator

    The turbine drives a generator, which converts the water's mechanical energy into electricity.

    Easy · Also offered: Compressor, Fan, Pump · Source: U.S. Department of Energy, How Hydropower Works

  23. Which invention drove much of the Industrial Revolution's mechanization?

    Steam engine

    Water wheels and windmills tied a mill to a particular river or to the weather. A coal-fired steam engine could be built anywhere and run all year, which is what let factories, mines and railways scale up.

    Easy · Also offered: Water wheel, Windmill, Tide mill · Source: Smithsonian, Steam engine

  24. What type of jet engine powers most modern airliners?

    Turbofan

    A turbofan sends most of its air around the hot core rather than through it, which makes it far quieter and much more fuel-efficient than the turbojets that powered the first airliners.

    Easy · Also offered: Turbojet, Ramjet, Pulsejet · Source: NASA Glenn, Turbofan engine

  25. What is the fixed pivot point of a lever called?

    Fulcrum

    A lever rotates about a fixed point called its fulcrum.

    Easy · Also offered: Load, Effort, Lever arm · Source: Encyclopaedia Britannica, Lever

  26. Which ions shuttle between the electrodes of the rechargeable batteries in phones and laptops?

    Lithium ions

    Charging drives lithium ions out of the cathode and into the graphite anode, where they sit between layers of carbon; discharging lets them travel back, and the electrons taking the long way round the external circuit are what power the device. Because that movement is reversible, the same cell can be run down and refilled hundreds of times.

    Easy · Also offered: Sodium ions, Zinc ions, Potassium ions · Source: U.S. Department of Energy, How lithium-ion batteries work

  27. What substance is applied between moving machine parts to reduce friction?

    Lubricant

    A lubricant holds a thin film between two surfaces so they slide across the film instead of grinding against each other. That cuts wear, saves the energy friction would otherwise waste, and keeps down the heat that grinding produces.

    Easy · Also offered: Coolant, Sealant, Solvent · Source: Encyclopaedia Britannica, Lubrication (direct source)

  28. What reaction releases energy in today's conventional power reactors?

    Nuclear fission

    Today's conventional power reactors release energy through nuclear fission rather than fusion, oxidation, or radioactive decay.

    Easy · Also offered: Nuclear fusion, Chemical oxidation, Radioactive decay · Source: U.S. Nuclear Regulatory Commission, How nuclear reactors work

  29. What law relates voltage, current, and resistance?

    Ohm's law

    Ohm's law states that voltage equals current multiplied by resistance for an ohmic conductor.

    Easy · Also offered: Hooke's law, Boyle's law, Bernoulli's principle · Source: U.S. National Institute of Standards and Technology, Ohm's law

  30. What minimum speed lets an object leave a body's gravity without further propulsion?

    Escape velocity

    Escape velocity is the speed required to break free from a celestial body's gravitational field.

    Easy · Also offered: Terminal velocity, Mach number, Drift speed · Source: NASA Glenn, Escape velocity

  31. What structures raise and lower ships through the Panama Canal?

    Locks

    Canal locks raise ships to Gatun Lake and lower them again to sea level.

    Easy · Also offered: Siphons, Dry docks, Weirs · Source: Panama Canal Authority, How the Canal works

  32. What engine component reciprocates inside a cylinder?

    Piston

    A piston is the engine component designed to travel back and forth within a cylinder. The alternatives are genuine engine components but operate elsewhere or serve different functions.

    Easy · Also offered: Valve, Connecting rod, Fuel injector · Source: Encyclopaedia Britannica, Piston

  33. What does water in a plumbing trap block?

    Sewer gases

    The standing water in a plumbing trap forms a seal that prevents sewer gases from flowing back into a building. If the water evaporates, those gases and odors can enter through the drain.

    Easy · Also offered: Combustion gases, Natural gas, Radon gas · Source: International Code Council, 2024 International Plumbing Code, Section 202 Definitions

  34. What simple machine uses a grooved wheel and rope?

    Pulley

    A pulley is a grooved wheel around which a rope or cable runs.

    Easy · Also offered: Lever, Wheel and axle, Inclined plane · Source: Encyclopaedia Britannica, Pulley

  35. An air-traffic control tower finds an aircraft's range and bearing by bouncing what off it?

    Radio waves

    Radar uses radio waves, which bounce off objects and return to the radar receiver to reveal their location. The word “radar” comes from “radio detection and ranging.”

    Easy · Also offered: Sound waves, Infrared waves, Laser light · Source: Federal Aviation Administration

  36. What is commonly embedded in concrete to help it resist tension?

    Steel reinforcing bars

    Concrete performs well in compression but poorly in tension, so steel reinforcement is embedded to carry tensile forces.

    Easy · Also offered: Aluminum sheets, Copper wire, Wooden beams · Source: The Concrete Society, Reinforced Concrete

  37. What does RPM measure?

    Revolutions per minute

    Revolutions per minute counts full turns of a shaft each minute, which is why a car's tachometer and a record player both use it.

    Easy · Also offered: Rotations per metre, Rate per minute, Rotational power measure · Source: International System of Units guidance

  38. Rocket thrust is usually explained by which of Newton's laws?

    Newton's third law

    A rocket engine hurls exhaust gas backwards at high speed and gets an equal and opposite push forwards. That is Newton's third law, and it is why a rocket works in the vacuum of space, where there is nothing outside to push against.

    Easy · Also offered: Newton's first law, Newton's second law, Newton's law of universal gravitation · Source: NASA, Rocket principles

  39. Which Roman waterworks brought fresh water from distant sources to cities?

    Aqueducts

    Roman aqueducts transported fresh water from distant springs and rivers into cities. The Pont du Gard in France is a remarkably preserved example, carrying water across the Gardon River on three tiers of arches.

    Easy · Also offered: Cisterns, Reservoirs, Siphons · Source: UNESCO, Pont du Gard

  40. A screw is a simple machine based on what?

    Inclined plane

    A screw is an inclined plane wrapped around a cylinder.

    Easy · Also offered: Wheel and axle, Pulley, Lever · Source: Encyclopaedia Britannica, Simple machine

All 90 engineering trivia questions · Trivia for kids in every category